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2005

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Articles 151 - 157 of 157

Full-Text Articles in Geology

Geologic Map Of The Bachelor Mountain 7.5' Quadrangle Beaverhead County, Montana, Susanne U. Janecke, R. J. Dorsey, J. C. Kickham, J. P. Matoush, W. Mcintosh Jan 2005

Geologic Map Of The Bachelor Mountain 7.5' Quadrangle Beaverhead County, Montana, Susanne U. Janecke, R. J. Dorsey, J. C. Kickham, J. P. Matoush, W. Mcintosh

Geosciences Faculty Publications

Geologic Map of the Bachelor Mountain 7.5’ Quadrangle Beaverhead County, Montana Geologic Summary The Bachelor Mountain quadrangle is located in the Horse Prairie Creek drainage basin of southwest Montana and contains exposures of Middle Proterozoic metasedimentary rocks and eighteen map units of Eocene to Oligocene basin-fill deposits assigned to the Medicine Lodge beds. Locally, overlying upper Oligocene to lower Miocene(?) Everson Creek beds and late early to early late Miocene Bannack Pass beds are also preserved as basin-fill deposits. The Medicine Lodge beds were deposited in an early basin, the Grant protobasin (Fig. 1a), during slip on the Muddy-Grasshopper detachment …

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Agraphorura Calvoi N. Sp. From Venezuelan Caves (Collembola: Onychiuridae), Javier I. Arbea Jan 2005

Agraphorura Calvoi N. Sp. From Venezuelan Caves (Collembola: Onychiuridae), Javier I. Arbea

International Journal of Speleology

A new species of Agraphorura (Collembola: Poduromorpha: Onychiuridae) from caves in the Nort-West of Venezuela is described. A. calvoi n. sp. can be distinguished from its congeners by the following combination of characters: antennal organ III with four papillae, 32/133/33343 dorsal pseudocellar formula, 3/000/0112 ventral pseudocellar, subcoxae each with two pseudocelli, postantennal organ with 7-9 vesicles, unguiculus with a basal lamella, tibiotarsi I-III with 19,19,18 setae (distal whorl of 9 setae). A table with the differential characters, as well as an identifi cation key for all of the known species of Agraphorura are provided.

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Cross-Formational Flow, Diffluence And Transfluence Observed In St. Beatus Cave And Sieben Hengste (Switzerland), Philipp Häuselmann Jan 2005

Cross-Formational Flow, Diffluence And Transfluence Observed In St. Beatus Cave And Sieben Hengste (Switzerland), Philipp Häuselmann

International Journal of Speleology

Observations in St. Beatus Cave and neighbouring caves revealed complex water flowpaths that can be used for explaining the behaviour of tracing experiments. The observations prove that even in vadose conditions, cross-formational flow, diffluences and transfluences are a quite common feature. Therefore, also the vadose karst has a very complex organisation.

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Partitions, Compartments And Portals: Cave Development In Internally Impounded Karst Masses, R. Armstrong L. Osborne Jan 2005

Partitions, Compartments And Portals: Cave Development In Internally Impounded Karst Masses, R. Armstrong L. Osborne

International Journal of Speleology

Dykes and other vertical bodies can act as aquicludes within bodies of karst rock. These partitions separate isolated bodies of soluble rock called compartments. Speleogenetically each compartment will behave as a small impounded-karst until the partition becomes breached. Breaches through partitions, portals, allow water, air and biota including humans to pass between sections of caves that were originally isolated.

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Radon In Caves, Arrigo A. Cigna Jan 2005

Radon In Caves, Arrigo A. Cigna

International Journal of Speleology

The physical characteristics of radon are reported as well as its sources,the transport in rock and its behaviour in caves. Then, the instruments,both active and passive, used for the measurement of radon concentration are discussed by taking into account their respective advantages and disadvantages for the use in the cave environment. Since in many countries radon is the object of regulations that were adopted for radiation protection purposes, this aspect is examined and the recommendations issued by international organisations and enforced in different countries are reported. Materials, methods and other remarks on the limits implementation are also listed with the …

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Cavity-Based Secondary Mineralization In Volcanic Tuffs Of Yucca Mountain, Nevada: A New Type Of The Polymineral Vadose Speleothem, Or A Hydrothermal Deposit?, Yuri V. Dublyansky, Sergey Z. Smirnov Jan 2005

Cavity-Based Secondary Mineralization In Volcanic Tuffs Of Yucca Mountain, Nevada: A New Type Of The Polymineral Vadose Speleothem, Or A Hydrothermal Deposit?, Yuri V. Dublyansky, Sergey Z. Smirnov

International Journal of Speleology

Secondary minerals (calcite, chalcedony, quartz, opal, fl uorite, heulandite, strontianite) residing in open cavities in the Miocene rhyolite tuffs of Yucca Mountain, Nevada have been interpreted by some researchers as "speleothemic" formations, deposited as a result of downward infi ltration of meteoric waters (DOE, 2001, Whelan et al., 2002). The major mineral of the paragenesis, calcite, shows spectacular trend of the textural and crystal morphology change: from anhedral granular occurrences, through (optional) platelet, bladed and scepter varieties, to euhedral blocky morphologies. The trend is consistent with the overall decrease in the supesaturation of the mineral forming solution. Stable isotope properties …

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Conceptualisation Of Speleogenesis In Multi-Storey Artesian Systems: A Model Of Transverse Speleogenesis, Alexander Klimchouk Jan 2005

Conceptualisation Of Speleogenesis In Multi-Storey Artesian Systems: A Model Of Transverse Speleogenesis, Alexander Klimchouk

International Journal of Speleology

Conceptual and respective quantitative models of speleogenesis/karstification developed for unconfined aquifers do not adequately represent speleogenesis in confined settings. A conceptual model for speleogenesis in confined settings is suggested, based on views about hydraulic continuity in artesian basins and close cross-formation communication between aquifers in multi-storey artesian systems. Soluble units sandwiched between insoluble porous/fissured formations (common aquifers) initially serve as low permeability beds separating aquifers in a confined system. Conduits evolve as result of vertical hydraulic communication between aquifers across the soluble bed ("transverse speleogenesis"). Recharge from the adjacent aquifer is dispersed and uniform, and flow paths across the soluble …

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